Rock sampling tool

ABSTRACT

In the sampling of a rock surface, dust that is formed by action of a compressed air driven rock cutting wheel is entrained in an air stream that is drawn into a shroud that surrounds all but a minor part of the cutting edge of the wheel and thence to a cyclone where it separates into a sample collector. High velocity exhaust air from the wheel-driving mechanism passes through an air ejector to provide a vacuum that causes the air stream to flow through the sample collecting system.

United States Patent [191 Reynolds [45] Oct. 22, 1974 [54] ROCK SAMPLINGTOOL [75] Inventor: John Windley Reynolds, Kimberley,

B. C., Canada [73] Assignee: Cominco, Ltd., Vancouver, British Columbia,Canada [22] Filed: Mar. 26, 1973 [21 Appl. No.: 344,638

[30] Foreign Application Priority Data Mar. 30, 1972 Canada 138576 [52]US. Cl 299/18, 73/425.2, 125/13, 173/30, 173/60, 175/58, 175/206, 299/64[51] Int. Cl. E2lc 37/22 [58] Field of Search 125/13; 73/425, 425.2;299/18, 64, 67, 89; 173/30, 60; 175/58, 60,

[56] References Cited UNITED STATES PATENTS 2,008,768 7/1935 Neal 173/60X 7/1939 Muncy 175/60 X 10/1940 St. Clair 299/89 Primary Examiner-ErnestR. Purser ABSTRACT In the sampling of a rock surface, dust that isformed by action of a compressed air driven rock cutting wheel isentrained in an air stream that is drawn into a shroud that surroundsall but a minor part of the cutting edge of the wheel and thence to acyclone where it separates into a sample collector. High velocityexhaust air from the wheel-driving mechanism passes through an airejector to provide a vacuum that causes the air stream to flow throughthe sample collecting system.

7 Claims, 2 Drawing igures ROCK SAMPLING TOOL particularly directed to arock sampling tool used pri-.

marily in geological exploration to take samples of exposed rocksurfaces. It provides easy means of getting good samples of such rocksurfaces or rock faces and can be sufficiently small and compact to beconveniently carried and operated by one man.

In the most commonly used method of rock face sampling, the geologistspreads a blanket below the surface to be sampled. He knocks chips offthe surface with hammer and chisel and collects the chips on theblanket. It is also known to drill a number of holes into the face ofthe rock and to collect sludge that is so formed. With chip sampling ofheterogeneous surfaces, the proportion of soft rock material collectedtends to be too high, and thus the samples collected are notrepresentative of the face sampled. With drill sampling, means must beprovided for collecting the sludge in a manner that avoids mixing ofsuccessive samples. In addition, frequent washing of equipment isessential.

SUMMARY OF THE INVENTION I have found that the foregoing disadvantagesof conventional rock sampling techniques and apparatus can besubstantially overcome by the sampling tool of the present invention bywhich shallow grooves are cut in a rock face by a rotating rock cuttingwheel and dust formed thereby is carried by an air stream into a shroudthat encases all but a minor portion of the cutting edge of the wheel.The air and entrained dust then flow to a cyclone where the dustseparates into a sample collector. The driving mechanism for the cuttingwheel or saw is operated by compressed air, the high velocity dischargestream of which provides suction to pull air and entrained rock dustthrough the sampling system. Improved sampling of a rock face is easilyobtained by making patterned, shallow saw cuts in the area to besampled. Dust from the saw cuts is drawn into the cyclone and isseparated into the sample collector. A short period of operation withoutcutting or with reverse flow of air discharged from the saw drivingmechanism through the open cyclone between samples purges the collectionsystem, thereby providing clean separation of successive samples. Thesample collector is supported in the open position on a frameworkattached to the base of the cyclone. A rubber band conveniently seals aplastic sample bag to the cyclone. Such a collector is very easilychanged between samples.

It is a principal object of the present invention to provide a rocksampling tool that is readily portable and operable by one man and whichpermits easy sampling of rock faces and the like rock surfaces.

It is another object of the present invention to provide a rock samplingtool which obtains representative samples of heterogeneous rock surfacesfor direct deposit into sample bags with clean separation of successivesamples.

BRIEF DESCRIPTION OF THE DRAWING A fuller understanding of the inventionmay be had by referring to the following description and claims, takenin conjunction with the accompanying drawing, in which:

FIG. 1 is an illustration of the sampling tool of the invention in itsoperative position; and

FIG. 2 is a schematic view of the sampling tool showing more clearly therelationship of component parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, sampling tooldriving mechanism 10, shown as a angle drill, is operated by highpressure air that enters through hose 11 and is controlled by throttle12 to rotate wheel 13 of a rock cutting saw. Shroud 14 encases the wheelexcept for a small segment of the cutting edge projecting from theshroud. Parallel edges 15 of shroud 14, disposed on either side of wheel13, serve as a depth gauge for the saw cuts.

Exhaust air from drill 10 flows through hose 16 to inlet 17 of ejector18 from which it is released through outlet 19. Rapid flow of this airstream through ejector 18, which operates as an aspirator, provides alow pressure zone or vacuum to draw air from the sampling system througha nozzle attached to opening 20. The sampling system comprises shroud 14which substantially envelops wheel 13, shroud off-take hose 21, cyclone22, sample collector 23 and cyclone off-take hose 24.

Rock dust that is formed during operation of cutting wheel 13 on a rockface is carried in an air stream passing into shroud 14 through hose 21tangentially into cyclone 22 where it separates under centrifugal forcesfrom the air and descends through the cyclone cone into collector 23.After separation of the dust, the air leaves cyclone 22 through a vortexoutlet by way of hose 24 to opening 20 of ejector 18 where it joins theexhaust air from drill 10.

The casing of saw driving mechanism 10 serves as a handle for convenientuse by operator 25. It is also convenient to suspend the ejector overthe operators shoulder, as shown, so that the cyclone and collector arepositioned in front of him. With flexible hose connections, the drilland saw can be rotated to cause edges 15 to move horizontally,vertically or diagonally over irregular rock faces. A unit with a smalldiameter wheel is capable of sampling quite irregular rock faces.

A rock sampling tool of the present invention was driven by aconventional air powered 90 angle drill that was 9 r inches long,weighed 2.2 pounds and rotated at 2,000 rpm with an air flow of 12 cfmat psi. The compressed air may be provided by a portable air bottle, ascuba type of which will operate the saw for about 8 minutes. Airentered the drill through a length of self-coiling plastic air supplyhose and its flow was controlled manually by depressing a throttle-thatwas attached to the drill casing. Exhaust air from the drill passedthrough a inch ejector and was vented behind the operator. The nozzle ofthe ejector was adjusted to apply effective vacuum to the samplingsystem for ingress of air into the shroud for entrainment of the dustformed by the cutting wheel and for its effective separation from theair flowing through the cyclone. A 3 34 inch diameter by inch shroudencased a 3 inch diameter cutting wheel to leave a small segment of thewheel, about k inch along a diameter, protruding beyond the straightedges of the shroud to limit the depth of a saw cut. The rim of thewheel was set with diamonds in a sintered matrix. This sampler cut a perminute. Air drawn into the shroud carried dust from the cutting zone tothe cyclone through hose that was attached to a tangentially mounteddust off-take on the shroud periphery. A 2 inch diameter cyclone wasused. A thimble-shaped wire supporting frame, about 6 inches long and linches in diameter was attached to the base of the cyclone. A plasticsample bag was sealed to the cyclone base with a rubber band. Thesampling tool operated effectively on dry and on wet rock faces. A cleancyclone before each sample was taken was assured by removal of thesample bag and momentarily closing the ejector exit. Exhaust air fromthe drill then blew out the open cyclone. Analyses for lead, zinc andiron in rock face samples obtained with this tool compared favorablywith those of samples obtained by the chipping method.

What we claim as new and desire to protect by letters patent of theUnited States is:

l. A rock sampling tool comprising, in combination, a compressed airoperated driving mechanism, a rock cutting wheel operatively connectedto said driving mechanism, a shroud substantially enveloping said rockcutting wheel excepting a segment of said cutting wheel projectingtherefrom, a cyclone having a vortex outlet and a conical base with adust sample collector removably attached to said conical base, an airejector, connecting means to carry exhaust air from said drivingmechanism to said air ejector for creating a low pressure zone therein,connecting means between the interior of the shroud and the cyclone andconnecting means between the cyclone vortex and the air ejector lowpressure zone whereby rock dust formed during operation of said cuttingwheel is carried into said collector.

2. A rock sampling tool as claimed in claim 1, in which said air ejectoris an aspirator whereby air exhausting from said compressed air operateddriving mechanism creates a low pressure therein which induces anairflow from the shroud to the cyclone to the air ejector through theconnecting means for collecting cut rock in the cyclone for dischargetherefrom.

3. A rock sampling tool as claimed in claim 1, in which said air ejectoris an aspirator whereby air exhausting from said compressed air operateddriving mechanism creates a low pressure therein which induces anairflow from the shroud to the cyclone to the air ejector through theconnecting means for collecting cut rock in the cyclone for dischargetherefrom.

4. A rock sampling tool as claimed in claim 1, in which said drivingmechanism is a angle drill.

5. A rock sampling tool as claimed in claim 4, in

which said air ejector is an aspirator whereby air exhausting from saidcompressed air operated driving mechanism creates a low pressure thereinwhich induces an airflow from the shroud to the cyclone to the airejector through the connecting means for collecting cut rock in thecyclone for discharge therefrom. 6. A method of sampling a rock facewhich comprises supplying air under pressure to a driving mechanismhaving a cutting wheel with an enveloping shroud operatively connectedthereto, feeding exhaust air from said driving mechanism to an airejector to create a low pressure zone therein, said shroud beingconnected to a cyclone having a vortex outlet and a dust collectorattached to the base thereof and said vortex outlet being connected tosaid air ejector low pressure zone, thereby causing an air stream toflow from said shroud to the cyclone and thence to the low pressure zoneof said air ejector whereby rock dust formed by operation of the cuttingwheel is entrained by the flowing air and is carried through the shroudand thence to the cyclone where it is separated from the air and fromwhich it is passed into said collector.

7. A rock sampling tool .comprising, in combination, a compressed airoperated driving mechanism, a rock cutting wheel operatively connectedto said driving mechanism, an air ejector operated by exhaust air fromthe driving mechanism to provide a low pressure zone therein, a shroudwhich substantially envelops said rock cutting wheel excepting a segmentof said cutting wheel projecting therefrom, a shroud off-take hose, acyclone, a sample collector sealed to the base of said cyclone, and acyclone off-take hose, said shroud offtake hose being adapted to carryair and entrained dust from said shroud to said cyclone, and saidcyclone offtake hose being adapted to carry air from the vortex outletof the cyclone to the low pressure zone of said air ejector.

1. A rock sampling tool comprising, in combination, a compressed airoperated driving mechanism, a rock cutting wheel operatively connectedto said driving mechanism, a shroud substantially enveloping said rockcutting wheel excepting a segment of said cutting wheel projectingtherefrom, a cyclone having a vortex outlet and a conical base with adust sample collector removably attached to said conical base, an airejector, connecting means to carry exhaust air from said drivingmechanism to said air ejector for creating a low pressure zone therein,connecting means between the interior of the shroud and the cyclone andconnecting means between the cyclone vortex and the air ejector lowpressure zone whereby rock dust formed during operation of said cuttingwheel is carried into said collector.
 2. A rock sampling tool as claimedin claim 1, in which said air ejector is an aspirator whereby airexhausting from said compressed air operated driving mechanism creates alow pressure therein which induces an airflow from the shroud to thecyclone to the air ejector through the connecting means for collectingcut rock in the cyclone for discharge therefrom.
 3. A rock sampling toolas claimed in claim 1, in which said air ejector is an aspirator wherebyair exhausting from said compressed air operated driving mechanismcreates a low pressure therein which induces an airflow from the shroudto the cyclone to the air ejector through the connecting means forcollecting cut rock in the cyclone for discharge therefrom.
 4. A rocksampling tool as claimed in claim 1, in which said driving mechanism isa 90* angle drill.
 5. A rock sampling tool as claimed in claim 4, inwhich said air ejector is an aspirator whereby air exhausting from saidcompressed air operated driving mechanism creates a low pressure thereinwhich induces an airflow from the shroud to the cyclone to the airejector through the connecting means for collecting cut rock in thecyclone for discharge therefrom.
 6. A method of sampling a rock facewhich comprises supplying air under pressure to a driving mechanismhaving a cutting wheel with an enveloping shroud operatively connectedthereto, feeding exhaust air from said driving mechanism to an airejector to create a low pressure zone therein, said shroud beingconnected to a cyclone having a vortex outlet and a dust collectorattached to the base thereof and said vortex outlet being connected tosaid air ejector low pressure zone, thereby causing an air stream toflow from said shroud to the cyclone and thence to the low pressure zoneof said air ejector whereby rock dust formed by operation of the cuttingwheel is entrained by the flowing air and is carried through the shroudand thence to the cyclone where it is separated from the air and fromwhich it is passed into said collector.
 7. A rock sampling toolcomprising, in combination, a compressed air operated driving mechanism,a rock cutting wheel operatively connected to said driving mechanism, anair ejector operated by exhaust air from the driving mechanism toprovide a low pressure zone therein, a shroud which substantiallyenvelops said rock cutting wheel excepting a segment of said cuttingwheel projecting therefrom, a shroud off-take hose, a cyclone, a samplecollector sealed to the base of said cyclone, and a cyclone off-takehose, saId shroud off-take hose being adapted to carry air and entraineddust from said shroud to said cyclone, and said cyclone off-take hosebeing adapted to carry air from the vortex outlet of the cyclone to thelow pressure zone of said air ejector.